Peep Show Series 4 “Holiday” where Mummy the dog meets an untimely demise.
Mad Men Season 4 “The Suitcase” where Peggy and Don bond while working an all nighter.
Breaking Bad: Season 4, episode 11, ‘End Times’. It’s where Jesse confronts Walt about poisoning Brock and Walt convinces him it was actually Gus. The intensity of the acting, and the sheer diabolical cleverness of Walt’s scheme makes that the undisputed best scene I’ve ever seen in a TV show.
Doctor Who: Season 3, episode 11, ‘Blink’. A thoroughly ingenious time-travel based story set in three different eras which starts in the middle, moves to the end, and then finishes at the beginning, but all makes perfect sense.
Game of Thrones: Season 3, episode 4, ‘And Now His Watch is Ended’: This episode has everything; intrigue, dragons, the sacking of Astapor, the introduction of Ramsay Snow, the death of Jeor Mormont, a trial by combat. It never lets up for a minute. Brilliant.